Horses are being used in an unconventional form of couples counseling at a Colorado ranch. (ABC News)(LOUISVILLE, Colo.) -- It's fascinating to watch a man trying to win back the love of his life by talking to a horse.

Horse therapy has been used for decades to help treat people with physical disabilities or learning disorders, but now they are also being used in an unconventional form of couples counseling.

Nancy Hamilton and Lottie Grimes are marriage therapists who run Relationship Ranch in Louisville, Colo. They are convinced that horses can help feuding couples make peace.

"You wouldn't think they would have any role in marriage therapy," Hamilton said. "But because horses are so exquisitely sensitive, they can help us determine what a couple is actually, really feeling."

For three weekends, "Nightline" followed one couple's last-ditch effort to save their crumbling relationship and attended their equine therapy sessions.

Justin and Lyz, both 30 and never married, have been together for nine years and have two sons. But lately, they said, the bickering and fighting at home got so bad that Justin reluctantly agreed to move out.

"We have piled problem on top of problem on top of problem for years," Lyz said. "Who knows what's at the bottom of that?"

Although he was skeptical about the healing powers of horses, he said he was willing to try just about anything to make his family whole again.

On their first day of therapy, the couple was introduced to the ranch's herd of horses. Justin was magnetically drawn to the newest and most aggressive horse, Danny, who came to the ranch after surviving a grizzly bear attack. Danny wasn't fitting in with the other horses, which hit home for Justin, who felt exiled from his own herd. Hamilton said horses can sense and read people's emotions.

"They're almost like a Rorschach projective test with a mane and a tail, where people can project onto them their feelings, their thoughts and their fears," she said.

Hamilton said she believes those fears can stem from what she called unresolved childhood wounds, which plague adult relationships. That was the case with Justin. When he was 9-years-old, his sister was brutally murdered by an ex-boyfriend and young Justin saw the murder scene.

"He chased her down and cut her throat," he said. "We went back several days later and they hadn't cleaned anything up."

After working with Justin and Lyz, Hamilton said Lyz saw Justin as controlling, but those tendencies are rooted in his childhood trauma.

"Trauma survivors are very concerned with being able to control their present environment because they were not able to control their environment when they were traumatized," she said.

Hamilton had Justin go through a blind trust exercise with Danny to force Justin to surrender control to his partner. The goal was to expose Justin's old wounds. Hamilton instructed him to talk to Danny about what had happened when his sister was killed. Danny, the trauma-surviving horse, set the stage for a major breakthrough.

"It seemed so stupid at first, and then it was actually helpful," Justin said. "Therapeutic."

Watching Justin talk to the horse, Lyz said she never saw him so vulnerable. After the session, the two apologized for hurting each other.

Two weeks later, Justin went through a final exercise to fully cope with his past. In a pen, surrounded by the herd, Justin became 9-years-old-again. He was instructed to confront his absent father through a role-playing exercise, while Lyz acted as a stand-in for his dad.

"You abandoned all of us," he said aloud. "I had to be the man of the family and I think that you're a coward."

During a crucial and emotional moment, Danny, the horse, seemed to sense that his new friend needed him, and he put his head into Justin's hands. Then, in a rare sign of trust, some of the other horses lay down behind Justin, while others joined him by his side.

"That was the big 'ah-ha' moment for Lyz," Hamilton said. "She said, 'Justin, I realize that I am abandoning you over and over again just like your dad did.'"

At that point, Hamilton told the couple to re-commit to each other exclusively. Suddenly, the horses started kicking and running. Hamilton said she believes they were reacting to Lyz's fear of commitment and Justin's fear of abandonment.

For now, the future of Justin and Lyz's relationship is still uncertain. Lyz said she needed more time to decide whether to continue the relationship. They haven't solved all of their problems, but at least for now, they have found some guidance for the long road ahead.

"If you truly want help you're going to do whatever it takes to get that, even if it's talking to a horse," Justin said.